Well packer apparatus having improved hydraulically-actuated anchor assembly

ABSTRACT

A first unitary slip located beneath the packing element is set from the surface by the operator by applying the weight of the tubing. Whenever the pressure beneath the packer exceeds the pressure above the packer which would normally cause the packer assembly to be moved upwardly within the casing, the excess pressure is used to drive a setting piston downwardly against a spring, the downward movement causing a setting sleeve to cause an upper unitary slip to rotate into contact with the casing and act as an anchor against upward movement of the tool. When it is desired to retrieve the overall assembly, pulling up on the tubing string causes the pressure to be equalized across the packer assembly and the tool can be removed from the borehole. The spring against which the setting piston works enables the apparatus to be run through fluid while moving through the borehole without a premature setting of the anchor assembly.

United States Patent Ellis Apr. 16, 1974 WELL PACKER APPARATUS HAVING [75] Inventor: Gary D. Ellis, Dallas, Tex.

[73] Assignee: Dresser Industries, Inc., Dallas, Tex.

[22] Filed: Apr. 9, 1973 [21] Appl. No.: 349,159

[52] US. Cl 166/120, 166/134 [51] Int. Cl E21b 23/04 [58] Field of Search 166/120, 134, 217

[56] References Cited UNITED STATES PATENTS 3,399,729 9/1968 McGill 166/120 3,426,846 2/1969 Young 166/120 X 3,548,936 12/1970 Kilgore et a1. 166/134 X 3,645,334 2/1972 McGill 166/120 3,714,984 2/1973 Read 166/134 3,731,740 5/1973 Douglas.. 166/120 3,735,814 5/1973 Tucker 166/217 Primary Examiner-David H. Brown Attorney, Agent, or Firm-John N. l-lazelwood; William E. Johnson, Jr.; Michael J. Caddell [57] ABSTRACT A first unitary slip located beneath the packing element is set from the surface by the operator by applying the weight of the tubing. Whenever the pressure beneath the packer exceeds the pressure above the packer which would normally cause the packer assembly to be moved upwardly within the casing, the excess pressure is used to drive a setting piston downwardly against a spring, the downward movement causing a setting sleeve to cause an upper unitary slip to rotate into contact with the casing and act as an anchor against upward movement of the tool. When it is desired to retrieve the overall assembly, pulling up on the tubing string causes the pressure to be equalized across the packer assembly and the tool can be removed from the borehole. The spring-against which the setting piston works enables the apparatus to be 7 run through fluid while moving through the borehole without a premature setting of the anchor assembly.

PATENTEDAPR 15 I974 5nd] 1 UP 3 FIG.

LAMW

PATENTEDAFR Is 1974 3804' 164 SHEET '3 0F 3 FIG.3

WELL PACKER APPARATUS HAVING IMPROVED HYDRAULICALLY-ACTUATED ANCHOR ASSEMBLY BACKGROUND THE INVENTION This invention relates generally to improved well tools and to improved hydraulic operated holddown gripping members for use on such well tools. More particularly, but not by way of limitation, this invention relates to an improved hydraulic operated holddown utilizing a slip of unitary construction that is pivotally mounted on the improved well tool and is arranged to hold the well tool against pressures in the well bore that are below the well tool.

Packers and other well tools constructed in accordance with the teaching of U.S. Pat. No. 3,548,936 and the disclosure of U.S. Pat. application Ser. No. 146,056 filed May 24, 1971, now U.S. Pat. No. 3,735,814 each of which is assigned to the assignee of the present application, have functioned satisfactorily, but certain problems have arisen due to the particular needs in remedial work required in servicing oilwells. It has long been the practice in the oil industry to use packers equipped with hydraulic operated holddown devices utilizing piston-type slips to hold the packer in position against pressures from below such oil tools. These devices have sometimes failed because the piston-type slips cannot be provided with sufficient resilient retracting devices to keep the teeth of the piston slips from wearing against the casing walls as the tools are moved in and out of the well bore, thus resulting in the packer moving up the hole when pressure is applied beneath the packer and therefore costing the well operator money in time and materials. It also should be appreciated that in remedial type operations, the setting or retrieving of the well tool should entail a minimum amount of tubing manipulation in order to avoid costly errors during such remedial service.

It is therefore the primary object of the present invention to provide an improved fluid pressure actuated retrievable packer that can be retrieved by exertion of an upward force on the mandrel.

Another object of the invention is to provide animproved pressure actuated hydraulically anchored retrievable packer that prevents inadvertent wear of the slip teeth during the insertion of the packer into and the removal of the packer from the well bore and means to positively retain the packer in set position when fluid pressure below the packer exceeds the pressure above the packer.

SUMMARY OF THE INVENTION The objects of the invention are accomplished, generally, by the provision of a retrievable packer with a fluid pressure actuated holddown anchor including an upper gripping member encircling a gripping member sleeve and mandrel that is moved into engagement with the casing when fluid pressure below the packer moves the setting piston into a downward position.

These and other objects, features and advantages of the present invention will be more readily appreciated from a reading of the following detailed specification and drawing, in which:

FIG.s 1, 2 and 3 are elevated views which together illustrate an elevated view, partly in cross section, of an apparatus according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing in more detail, there is shown in FlG.s 1, 2 and 3 an improved well tool generally designated by the reference character 10. The well tool 10 at its upper end includes a coupling 12. The well tool 10 also includes a mandrel 20 having its upper end threadedly connected to coupling 12 and its lower end threadedly connected to gudgeon coupling 118. The coupling 12 is provided with a thread (not shown) for connecting the tool 10 with the tubing (not shown) that is used for running the well tool 10 into a well bore (not shown). The well tool 10 also includes an elongated tool body 16 that is comprised of a plurality of components that are threadedly connected to facilitate the manufacture of the tool body 16. A gripping member sleeve 18 is encircled by a portion of the tool body 16 in sliding relationship thereto and extending upward therefrom. The gripping member sleeve 18 is slideably mounted on mandrel 20, and O-ring 22 mounted in groove 24 provides a slideable fluid-tight seal between mandrel 20 and gripping member sleeve 18. Upon the exterior of tool body 16 is setting chamber housing 25 that extends coaxially along a portion of the tool body 16 and extends over a portion of gripping member sleeve 18. O-ring 28 is located in groove 30 in setting chamber housing 25 to form a slideable fluid-tight seal between gripping member sleeve 18 and setting chamber housing 25 allowing a portion of gripping member sleeve 18 to move axially through the setting chamber housing 25. A portion of setting piston 32 is encircled by setting chamber 25 extending into balance chamber housing 34 with one end encircled by balance valve 36. One end of setting piston 32 is threadedly attached to gripping member sleeve 18. Setting piston 32 may move axially within portions of setting chamber housing 25 and balance chamber housing 34. A fluid-tight seal is provided between setting piston 32 and setting chamber housing 25 by O-ring 38 within groove 40.

Setting chamber 128 is formed in the annulus between setting chamber housing 25 and setting piston 32 and gripping member sleeve 18 between O-ring 22 and O-ring 38. Setting chamber 128 is ported into the longitudinal passageway 124 through setting chamber port 126. O-ring 42 within groove 44 forms a slideable fluidtight seal between a portion of setting piston 32 and balance valve 36. Balance chamber housing 34 encircles balance valve 36. O-ring 46 within groove 48 provides a fluid-tight slideable. seal between balance valve 36 and balance chamber housing 34. Balance chamber 132 is formed in the annulus between setting sleeve housing 25, balance chamber housing 34 and setting piston 32 between O-ring 38, O-ring 42 and O-ring 46. Balance chamber 132 is ported into the annulus between tool body 16 and the conduit (not shown) through balance chamber port in balance chamber housing 34.

A face seal housing 50 is encircled by a portion of balance chamber housing 34. O-ring 52 located in groove 54 provides a slideable fluid-tight seal between face seal housing 50 and balance chamber housing 34. Face seal 60 is encircled by a portion of face seal housing 50 and maintained in position by face seal insert 62 encircled by a portion of face seal housing 50. Face seal housing 50 encircles annular groove 56 on mandrel 20 and is held in relative position by two half ring valve keepers 58 seated in annular groove 56 in mandrel and encircled by recess 64 in the valve seal housing 50. Flange 68 on valve seat insert 62 abuts against end of recess 64 and split ring valve keeper 58 which is held within recess 64 by retainer ring 60 located in groove 66 located within recess 64 of valve seal housing 50. Spring rest 70, encircling mandrel 20, abuts against face seal housing 50. Spring 75 is disposed around manv drel 20 and is biased against spring rest 70 and one end of setting piston 32.

Gripping member 72 encircles a portion of gripping member sleeve 18 in sliding relation thereto and is biased to an unset position by spring 73. Lug 74 on gripping member sleeve 18 is arranged to engage surface 76 on the gripping member 72 to exert an unsetting force on the gripping member 72 during release of the well tool 10, such release to be described hereinafter. The gripping member sleeve 18 extends through the gripping member 72 that is arranged for pivotal motion on the mandrel 20 and the gripping member sleeve 18. Sleeve 18 is provided with a pair of elongated slots 13 passing through opposite sides of the sleeve. A pair of opposed pins 11 are securedly engaged in gripping member 72 and project inwardly into slidable engagement in opposed slots 13 of sleeve 18. A slot 13 and pin 11 on one side of the tool are disclosed in phantom in FIG. 1. When gripping member sleeve 18 is moved further into tool body 16, active end 78 of gripping member 72 will move into engagement with abutment 80 that encircles gripping member sleeve 18.

Valve seat 82 (illustrated in FIG. 2) slidingly encircles the mandrel 20 below the toolbody l6 and includes an upper packer thimble 84 that is in engagement with the uppermost of a plurality of resilient packer rings 86. Valve seat lip 122 is on one end of valve seat 82 to make a fluid-tight seal when forced against the face seal 60 of FIG. 1. The lowermost of the packer rings 86 is in engagement with the lower packer thimble 88. The lower packer thimble 88 is also slidingly disposed on the mandrel 20 and terminates at its lower end in a downward facing lower head abutment 92.

A passageway 124 extends into setting chamber 128 through setting piston port 126 by means of the annular space continuous between the mandrel 20 and setting piston 32, balance valve 36, face seal housing 50, face seal insert 62, valve seat 82, upper packer thimble 84, packer rings 86, lower packer thimble 88 into the annular space between conduit (not shown) and thimble 88 through port 89.

A lower slip sleeve 94 slidingly encircles the mandrel 20 and has an outwardly extending slip carrier retainer 96 on its upper end that is disposed within and engages the interior of the lower thimble 88. The slip sleeve 94 extends through a lower gripping member 98 that is constructed similar to the upper gripper member 72 except that it is inverted on the well tool 10. The lower gripping member 98 includes spring 100 that has one end engaged with lower slip spring sleeve 94 to aid in urging the lower gripping member 98 toward the retracted position as illustrated in FIG. 3. The lower gripping member 98 includes an upper or active end 102 and a lower or passive end 104. The upper end 102 is engageable with the lower head abutment 92 while the lower end 104 is engageable with an upward facing abutment 106 on a drag block assembly 1 12. The lower end of the slip sleeve 94 is formed into an exterior flange 110 that is disposed within drag block assembly 112 and biased upward by resilient ring 113. As constructed, the drag block assembly 112 is movably positioned on the mandrel 20 for both the rotational and longitudinal movement. Such movement is controlled by gudgeon 114 on gudgeon coupling 118 threadedly attached to mandrel 20 so that gudgeon 114 operates in relationship to jay-slot 116 formed in drag block assembly 112. Between the abutment 106 formed on the drag block assembly 112 and the jay-slot 116, a plurality of spring-loaded drag blocks are located in the opening of the body of the drag block assembly. The drag blocks 120 are arranged to frictionally engage the interior wall of a well conduit (not shown) as the well too] 10 travels therethrough so that the relative movement can be accomplished between the various movable components of the tool 10 as is well known in the oil tool art.

In the operation of the apparatus illustrated with respect to FlG.s 1, 2 and 3, the well tool 10 is shown therein in the unset position. The well tool 10 is normally to be set in a conduit or casing (not shown) normally disposed within a well bore (not shown). Upon reaching the desired position in a well bore for setting the well tool 10, a tubing (not shown) connected to the upper end of the tool is rotated to the right and lowered so that the gudgeon 114 formed on the gudgeon coupling 118 moves downward with respect to the jay-slot 116 in the drag block assembly 112. Due to the frictional engagements of the drag blocks 120 with the conduit (not shown), the drag block assembly 112 and the lower gripping member 98 remain in a relatively fixed position. The upper gripping member 72, the tool body 16, the upper thimble 84, the packing rings 86 and the lower thimble 88 move downwardly with the mandrel 20. The downward movement brings the downward facing abutment 92 into engagement with the upper or active end 102 of the lower gripping member 98 causing the lower gripper member 98 to rotate into set position as tool body 16, also traveling downward, causes face seal 60 to abut against valve seat lip 122. Additional downward movement of the mandrel 20 exerts a force through face'seal 60 against valve seat lip 122, the valve seat 82 and upper packer thimble 84 deforming the packer rings 86 outwardly into sealing engagement with the conduit (not shown). When the packing rings 86 are fully deformed, further downward movement of the upper thimble 84 is prevented, and the full force of the tubing (not shown) is exerted on the lower gripping member 98. When face seal 60 abuts against valve seat lip 122, a passageway 124 is formed in the annular space between lower packer thimble 88 and mandrel 20 and the annular space between tool body 16 and mandrel 20 from the annular space between lower packer thimble 88 and the conduit (not shown) to the setting piston port 126 and into setting chamber 128. Balance chamber port 130 leads from the annulus between conduit (not shown) and tool body 16 into balance chamber 132. With the packer rings 86 sealed against the conduit (not shown) and the pressure in the conduit below packing rings 86 greater than the pressure in the conduit annulus above packing rings 86 and outside of tool body 16 working against the effective piston area between O-ring 38 and O-ring 42, fluid in balance chamber 132 is forced out through balance chamber port 130 causing setting piston 32 to compress spring 72. This action draws gripping member sleeve 18 further into setting chamber housing 25, thus causing the active end 7% of upper gripping member 72 to contact the abutment 80 of tool body 16 and causes the upper gripping member 72 to rotate into set position against the conduit (not shown). In this manner, the well tool 10 is prevented from being moved upward by the higher pressure in the conduit below lower packer thimble 88.

When fluid pressure above packing rings 86 in the annulus between tool body 16 and conduit (not shown) is greater than the fluid pressure below packing rings 86 in the annular space between lower thimble 88 and the conduit, the higher pressure enters balance chamber 132 through balance chamber port 130 and forces the setting piston 32 to move gripping member sleeve 18 upward causing lug 74 to push against surface 76 of upper gripping member 72 rotating gripping member 72 into the unset position. Fluid in setting chamber 128 is forced into passageway 124 through setting piston port 126. The pressure working against the annular area between O-ring 42 and O-ring 46 on balance valve 36 pushes the balance valve 36 against valve seal housing 50, thus preventing the face seal 60 from being disengaged from valve seat lip 122.

lt should be appreciated that the well tool 10 as illustrated is a retrievable tool. That is, the well tool 10 can be unset and removed from the conduit when desired. Retrieval is accomplished by pulling on the tubing (not shown) and the mandrel 20 with a sufficient force to cause the face seal 60 to be pulled away from valve seat lip 122, thus causing the pressures above and below packing rings 86 to equalize. Continued upward movement of mandrel 20 and face seal housing 50 exerts force on spring 75 causing it to compress the push against the bottom of setting piston 32 and thus against gripping member sleeve 18, causing lug 74 to exert force against surface 76 of upper gripping member 72. This action releases gripping member 72 from contact with the conduit or casing and rotates the gripping member 72 into the retracted position illustrated in FIG. 1. The continued upward movement of mandrel 20 pulls gudgeon coupling 118 against drag block assembly 112 forcing abutment 106 against the passive end 104 of lower gripping member 98, thus lifting and rotating the gripping member 98 into the retracted position illustrated in FIG. 3. As soon as the upper gripping member 72 and the lower gripping member 98 have been returned to retracted position as illustrated in FlG.s l, 2 and 3, the well tool 10 is in condition to be removed from the well bore. Alternately, by rotating the tubing (not shown) and mandrel 20 to the left, the gudgeon 114 will re-engage jay-slot 116 and the well tool 10 can be lowered further into the well bore.

Thus, it should be appreciated that there has been described and illustrated herein the preferred embodiment of a well packer appratus having an improved anchor assembly for holding the packer against movement upwardly within the well bore which would normally result from a pressure differential across the packer assembly. Of special importance to the invention is the spring 75 which enables the apparatus to be run into a well bore on a tubing string from the earth's surface while traversing through fluids within the well bore which could cause the setting piston 32 to prematurely set and cause the upper gripping member 72 to rotate into position. However, obvious modifications will occur to those skilled in the art and other resilient means could be used to bias the setting piston 32 in place within the well packer apparatus 10.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A well tool useful in a well bore or the like, comprising:

an elongated body movable longitudinally through the well bore;

packing means carried by said body, said packing means being sealingly engageable with the wall of said well bore, whereby a pressure differential can build up between first and second sides of said packing means as measured along the length of said well bore; first hollow gripping member pivotal with respect to said body and located on a first of said sides of said packing means, said first gripping member being pivotable into engagement with the wall of said well bore;

a second hollow gripping member pivotal with respect to said body and located on a second of said sides of said packing means, said second gripping member being pivotable into engagement with the wall of said well bore; and 7 means responsive to said pressure differential to cause said second gripping member to pivot into engagement with the wall of said well bore.

2. A well tool useful in a well bore or the like, comprising:

an elongated body movable longitudinally through the well bore;

first and second hollow gripping members pivotal with respect to said body and spaced apart along the length of said body, each of said gripping members being pivotable into engagement with the wall of said well bore;

packing means carried by said body intermediate of said gripping members, said packing means being sealingly engageable with the wall of said well bore, whereby a pressure differential can build up across said packing means; and

means responsive to said pressure differential to cause one of said gripping members to pivot into engagement with the wall of said well bore.

3. The well too] according to claim 2, said pressure responsive means being further characterized as comprising:

a setting piston responsive to said pressure differential;

a gripping member sleeve responsive to the movement of said setting piston, said sleeve being connected to said one of said gripping members; and

abutment means carried by said well too] whereby said one of said gripping members is caused to rotate upon relative movement between said sleeve and said abutment means.

4. The well tool according to claim 3, said pressure responsive means being further characterized by resilient means connected to and acting against said setting piston, thereby lessening the probability of a premature setting of said one gripping member as well tool traverses the well bore. 

1. A well tool useful in a well bore or the like, comprising: an elongated body movable longitudinally through the well bore; packing means carried by said body, said packing means being sealingly engageable with the wall of said well bore, whereby a pressure differential can build up between first and second sides of said packing means as measured along the length of said well bore; a first hollow gripping member pivotal with respect to said body and located on a first of said sides of said packing means, said first gripping member being pivotable into engagement with the wall of said well bore; a second hollow gripping member pivotal with respect to said body and located on a second of said sides of said packing means, said second gripping member being pivotable into engagement with the wall of said well bore; and means responsive to said pressure differential to cause said second gripping member to pivot into engagement with the wall of said well bore.
 2. A well tool useful in a well bore or the like, comprising: an elongated body movAble longitudinally through the well bore; first and second hollow gripping members pivotal with respect to said body and spaced apart along the length of said body, each of said gripping members being pivotable into engagement with the wall of said well bore; packing means carried by said body intermediate of said gripping members, said packing means being sealingly engageable with the wall of said well bore, whereby a pressure differential can build up across said packing means; and means responsive to said pressure differential to cause one of said gripping members to pivot into engagement with the wall of said well bore.
 3. The well tool according to claim 2, said pressure responsive means being further characterized as comprising: a setting piston responsive to said pressure differential; a gripping member sleeve responsive to the movement of said setting piston, said sleeve being connected to said one of said gripping members; and abutment means carried by said well tool whereby said one of said gripping members is caused to rotate upon relative movement between said sleeve and said abutment means.
 4. The well tool according to claim 3, said pressure responsive means being further characterized by resilient means connected to and acting against said setting piston, thereby lessening the probability of a premature setting of said one gripping member as well tool traverses the well bore. 